<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>Document</title>
    <style>
        div {
            border: 1px solid;
        }

        #div1 {
            height: 400px;
            width: 400px
        }

        #div2 {
            height: 300px;
            width: 300px
        }

        #div3 {
            height: 100px;
            width: 100px
        }
    </style>
</head>

<body>
    <div id="div1">
        div1
        <div id="div2">
            div2
            <div id="div3">
                div3
            </div>
        </div>
    </div>
</body>
<script src="http://libs.baidu.com/jquery/1.11.3/jquery.min.js"></script>
<script>
    // 事件冒泡，从最具体的开始依次向外层冒泡
    $("#div1").click(
        function (event) {
            console.log("div1")
        }
    );
    $("#div1").on("click","#div2",
        function (event) {
            console.log("div2")
        }
    );
    $("#div2").click(
        function (event) {
            console.log("div2");
        }
    );
    $("#div3").click(
        function (event) {
            console.log("div3")
        }
    );
</script>

</html>